System-Level Operational and Adequacy Impact Assessment of Photovoltaic and Distributed Energy Storage, with Consideration of Inertial Constraints, Dynamic Reserve and Interconnection Flexibility

Abstract

Abstract:The growing penetration of solar photovoltaic (PV) systems requires a fundamental understanding of its impact at a system-level. Furthermore, distributed energy storage (DES) technologies, such as batteries, are attracting great interest owing to their ability to provide support to systems with large-scale renewable generation, such as PV. In this light, the system-level impacts of PV and DES are assessed from both operational and adequacy perspectives. Different control strategies for DES are proposed, namely: (1) centralised, to support system operation in the presence of increasing requirements on system ramping and frequency control; and (2) decentralised, to maximise the harnessing of solar energy from individual households while storing electricity generated by PV panels to provide system capacity on request. The operational impacts are assessed by deploying a multi-service unit commitment model with consideration of inertial constraints, dynamic reserve allocation, and interconnection flexibility, while the impacts on adequacy of supply are analysed by assessing the capacity credit of PV and DES through different metrics. The models developed are then applied to different future scenarios for the Great Britain power system, whereby an electricity demand increase due to electrification is also considered. The numerical results highlight the importance of interconnectors to provide flexibility. On the other hand, provision of reserves, as opposed to energy arbitrage, from DES that are integrated into system operation is seen as the most effective contribution to improve system performance, which in turn also decreases the role of interconnectors. DES can also contribute to providing system capacity, but to an extent that is limited by their individual and aggregated energy availability under different control strategies.

Minimization of Power Losses through Optimal Battery Placement in a Distributed Network with High Penetration of Photovoltaics

“…In this study, three main models are integrated with the distribution system, which are photovoltaic systems, and battery energy storage systems and loads. The increase installations of PV systems in the DNs have transformed the flow of electrical power to be more of a bidirectional flow instead of a fixed direction as the case of a radial configuration [32]. Although this transformation of electrical power flow is beneficial from a technical and financial point of view, it also brings in a few technical challenges.…”

System-level assessment of reliability and resilience provision from microgrids

“…These CHP units will have the potential to operate as microgrids, and therefore it becomes critical to quantify to what extent they can contribute to system operation. Similarly, the PV installation, mostly domestic rooftop panels, in the British electricity system is expected to be 36.7 GW by 2040, and when coupled to distributed electricity storage (expected to have an installed capacity of 12.5 GW by 2040 [33]) they could contribute to different services [34].…”

“…Table 3 presents the generation portfolio of the test British electricity system in 2015 [51] and the corresponding average availability of the generation technologies. The detailed models of solar and wind generation at system---level have been described in [34] and [53], respectively. More specifically, the seasonal and geographical features of solar generation come from the models in [34] that correspond to the solar generation when modelled directly at a national level (i.e., modelling the aggregated solar generation of the test British system using historical solar irradiance at 11 representative locations as well as corresponding installed PV capacities across the British system [34]).…”

“…The detailed models of solar and wind generation at system---level have been described in [34] and [53], respectively. More specifically, the seasonal and geographical features of solar generation come from the models in [34] that correspond to the solar generation when modelled directly at a national level (i.e., modelling the aggregated solar generation of the test British system using historical solar irradiance at 11 representative locations as well as corresponding installed PV capacities across the British system [34]). It has to be highlighted here that this is different comparing the modelling of PV outputs of MG2 (which are modelled based on the solar irradiance of the aforementioned seven typical days and also included in the Annex), as described in the framework for modelling individual microgrids.…”

Impact of Energy Losses Due to Failures on Photovoltaic Plant Energy Balance

“…Nevertheless, with the PR it is impossible to know clearly the energy losses related to failure with respect to the energy losses related to inefficiencies in the PV plant. If the PV plant would include batteries, the energy balance could also be affected by the control strategies for energy store [31].…”